'Thanks' and 'Thank you'

[Grammarholic]

Question. The only thing I want to know is if 'Thanks' and 'Thank you' are followed by a comma or period at the end of an informal e-mail. Which is preferred and is truly correct in each set below -- the period or the comma?

I would love Mr. Micawber's input on this (if he's 'in the house').

Set 1

1. Hey, Bert. Nice working with you on Thursday and Friday. How do I go about getting that inventory sheet-- the one that had the actual call-in, then the adjustments that were made in red font (in parentheses)?

Thanks,

John

2. Hey, Bert. Nice working with you on Thursday and Friday. How do I go about getting that inventory sheet-- the one that had the actual call-in, then the adjustments that were made in red font (in parentheses)?

Thanks.

John
__

Set 2

1. Hey, Bert.. Nice working with you on Thursday and Friday. How do I go about getting that inventory sheet-- the one that had the actual call-in, then the adjustments that were made in red font (in parentheses)?

Thank you,

John

2. Hey, Bert.. Nice working with you on Thursday and Friday. How do I go about getting that inventory sheet-- the one that had the actual call-in, then the adjustments that were made in red font (in parentheses)?

Thank you.

John

[Mordant]

I vote for the comma. It is consistent with the standard means of closing letters. If I were to use the period, I would include "thanks" or "thank you" in the body and end with a different closing. Informal e-mails, however, sometimes have no closing at all. If you feel comfortable enough to use fragments in the body, as you have, then it really doesn't seem to matter much whether you use a period or a comma.